STEWART: OSTEOLOGY OF ANOGMIUS POLYMICRODUS. II9 



Measurements: 



Length of mandible from cotylus 204 mm. 



Depth at coronoid process 65* " 



Depth at symphysis 17 " 



Length of tooth-band 115* " 



The bone originally described as a premaxilla* may be a ptery- 

 goid, as it can hardly be a vomer or palatine from the description 

 of these parts as given by Professor Cope. It is slightly curved 

 longitudinally and has a broad tooth-band on one surface which 

 bears denticles slightly larger than those on the parts described 

 above. On the opposite surface from the tooth-band there is a 

 ridge extending its full length which is overhanging on one side, 

 thus forming a groove which is evidently for the reception of some 

 other bone. 



Measurements: 



Length of tooth-band 6g mm. 



Greatest width of tooth-band 17 " 



There are two other bones which are covered with small pits 

 and somewhat resemble those found on the tooth-bearing elements 

 described above, although it is likely that these bones never bore 

 teeth. One of these is a cardiform bone, probably a pharyngeal. 

 The pitted surface is slightly depressed in the middle and the sides 

 slope sharply toward the edges. The other element is not so thick 

 as the one just mentioned; it has a broad band of these pits on one 

 side and a median ridge on the other, somewhat similar to that 

 found on the supposed pterygoid described above. At one of the 

 ends there is a roughened articular surface. There is another 

 long and slender element that bears a certain resemblance to the 

 palatine(?) bone of Siratodiis apicalis Cope, which is no doubt the 

 same bone described as a palatine by Professor Cope.f It is 

 broader at one end than at the other. The lower(?) surface is 

 covered with pits similar to those described above, but there are no 

 teeth present in any of the specimens that I have examined. The 

 upper surface is somewhat striated at the anterior(?) extremity. 

 The ceratohyal is broad and thin, concave at the posterior end and 

 somewhat irregular in outline at the other, where there are two 

 surfaces for the hypo- and uro-hyals respectively. The bone seems 

 to be striated, especially so toward the extremities. Its length 

 is 98 mm. 



*l. c, p. 195. 



•tProq. Ana. Phil. 60c., 1879, p. 179. 



